There is a lot that goes on prior to harvest, in many farms, uptake for important nutrients such as Potassium, Calcium, and even Phosphorus will only continue to increase. Pro K™ is highly efficient, certified for organic use, and an excellent tank-mix partner, especially when compared to sulfate of potash (SOP).
Sulfate of Potash(SOP) has been our only option for organic Potassium
Limiting factors include solubility for >5% spray solution unless using dry powder
Sulfur = 18%, may limit rates where Sulfur adds to anaerobic soil conditions
Soils >25-40 ppm may not be a candidate for K applications
Always know the K amount in water source (20-40 ppm)
Use care when using on high Mg soils or in mixes with Mg (Epsom Salts).
The salt index is around 50 which is acceptable
Can be unavailable for soil apps w/ Al like Eastern soils or any cool/damp conditions
K is better managed as light and frequent applications as a sprayable
Potassium easily leeches from sandy soils as a granular with rainfall
Coated K materials have light release rates, hard to see plant corrections in plants and/or fruit
Correctly measured soil K requirements should calculate: colloidal, extractable, and soluble K as the total